Which of the following numbers is a prime number?

Question

Solutons With Key Points

Answer- A

Step 1: Find a whole number 'X' for each number such that X2 > the number;

13² > 167

15² > 213

19² > 350

21² > 437

Step 2: Get all the prime numbers that are less than 'X'.

Prime numbers less than 13 are 2, 3, 5, 7, and 11

Prime numbers less than 15 are 2, 3, 5, 7, 11, and 13

Prime numbers less than 19 are 2, 3, 5, 7, 11, 13, and 17

Prime numbers less than 21 are 2, 3, 5, 7, 11, 13, 17, and 19

Step 3: Check divisibility of each number with prime numbers which are less than 'X'.

167 is not divisible by any prime number

213 is divisible by 3

352 is divisible by 2 and 11

437 is divisible by 19

167 is the required prime number as it is not divisible by any prime number.